1. Field of the Invention
The present invention relates to a hoist suspension frame for moving cargo onto and off of a flatbed trailer chassis. More particularly the present invention comprises a temporary steel frame which can be removably mounted on a flatbed trailer chassis. The frame extends laterally from the trailer chassis to permit a hoist mechanism to move cargo between the trailer bed and points adjacent the trailer.
2. Description of the Prior Art
The use of various types of machinery in one form or another for the purpose of moving cargo onto and off of a flatbed trailer chassis is known in the prior art. Numerous designs, structures, and forms of apparatuses, and a variety of methods, are disclosed by and utilized in the prior art. These have been developed for the accomplishment of both the general and specific objectives, purposes, and requirements of cargo handling, and specifically for loading and unloading trailer chassis.
Almost all cargo, apart from cargo containers which must be handled by specialized cranes due to size or weight, is now loaded onto and off of flatbed trailers by motor-powered forklift trucks. Cargo packages are no longer lifted directly by dock workers due to considerations of size and weight, and because safety rules prevent or at least inhibit direct handling.
Forklift trucks usually lift a single item, or multiple identical items if they are stacked. A lift truck must make multiple trips to unload a trailer flatbed chassis because of its limited load carrying capacity in comparison with the load carrying capacity of a flatbed chassis. Forklift trucks also must offload a trailer from both sides of the chassis because of the limited forward reach of their forks.
The trolley frame contemplated according to the present invention departs substantially from the conventional concepts and designs taught and used by the prior art, and in doing so, provides an apparatus primarily developed for the purpose of overcoming the problems as described above, but it accomplishes the result in a different and improved manner for handling cargo loads more easily, quickly, conveniently, accurately, and economically. The present invention effectively provides removable machinery which can be temporarily mounted to a flatbed trailer chassis to unload and offload cargo to and from any area on the chassis bed to or from locations to either side of the chassis.